Resumen de Optimal peripheral access using pipe-bassed double-buffering
When working with slow peripherals such a tape drivers and CD-Recorders, careful tunning of the access patterns and process architecture can result in substantial increase in performance. One of the responsabilities of an opperating system is to optimize the utilization of a computer system by the appropiate scheduling of tasks. Thus, when process waits for a peripheral to complete an operation, the OS can schedule other processes that are waiting to run. Although schedulling happens behind the scenes of normal system operation and is transparent to the user, in some cases one can optimize execution time by cacrefully arranging interdependent tasks. With ever-increasing processor speeds and with peripheral access times relatively stagnant, such optimizations can deliver impressive results. I will describe and explain how I reduced the overhead of tape access by almost 30 percent by simply adding two dd(1), commands to our backup pipeline.
